Field of the Invention
This invention relates to new methods and compounds for determining lithium level in serum or other samples suspected of containing lithium, and more particularly to a homogeneous colorimetric method that is performed directly on the sample without deproteinization. Lithium in the form of lithium carbonate is administered to manic-depressive patients. The therapeutic range of lithium ion in plasma is quite narrow, namely, 0.8 to 1.2 mM. It is important to monitor the lithium level in such patients because of the toxic side effects that appear when the lithium level in blood exceeds the recommended level.
Current methods for detecting and determining lithium generally involve flame emission or atomic absorption methods. These techniques are disadvantageous because they are slow and labor intensive.